Multimodal Treatment of a Peripheral Primitive Neuroectodermal Tumor Originating From the Thoracic Cavity in a Dog

Area of Science:

• Veterinary Oncology
• Comparative Pathology

Background:

• Peripheral primitive neuroectodermal tumor (pPNET) is an exceptionally rare and aggressive malignancy in young dogs.
• Limited veterinary literature exists, with only four previously reported necropsy cases.

Observation:

• A 1.5-year-old French Bulldog presented with progressive forelimb lameness and Horner's syndrome.
• Imaging revealed a large mediastinal mass with vertebral canal invasion and multifocal metastases.

Findings:

• Histopathology and immunohistochemistry confirmed pPNET.
• Precision diagnostics, including DNA sequencing and chemosensitivity assays, guided multimodal treatment (chemotherapy, radiation, immunotherapy, targeted therapy).
• Partial remission was achieved 3.5 months post-presentation.

Implications:

• This case demonstrates the application of advanced diagnostics and tailored multimodal therapy for canine pPNET.
• Despite initial response, aggressive metastatic progression led to euthanasia, underscoring the challenges in treating this rare tumor.
• Further research into novel therapeutic strategies for pPNET is warranted.